Furniture Design
This domain tests design decisions that can be justified: ergonomics, standard dimensions, proportion, material choice and the design process. Answers earn marks when they quote a dimension and explain who it suits.
Standard dimensions to know
- Dining table 720–750 mm high; chair seat 450 mm; the 250–320 mm difference between them is the working rule.
- Desk 720–750 mm; knee clearance at least 600 mm wide, 450–600 mm deep and 600–620 mm high.
- Kitchen base units 850–900 mm high, 600 mm deep; wall units 300–350 mm deep, 500–600 mm above the worktop, so 1400–1500 mm from the floor.
- Wardrobe 600 mm deep; hanging rail about 1000–1200 mm from the floor for shirts, 1500–1700 mm for long coats; shelves 300–400 mm apart.
- Beds 1900 or 2000 mm long; single 900 mm, double 1400/1600 mm wide.
Anthropometrics
Design for a range, not an average: 5th percentile female to 95th percentile male. Provide adjustability where a single size cannot serve both - seat height, desk height, shelf positions. Consider reach zones, clearance for knees and feet, and access for people with reduced mobility.
Principles and process
Brief → research → sketch → scale drawing → mock-up → prototype → production. Design language: proportion (the golden ratio, roughly 1:1.618), balance, rhythm, unity, honest use of material. Structure must be resolved on paper: leg positions, rail heights, joint choice, knock-down fittings for transport.
Materials and standards
Choose by function: beech for bent frames, oak for wear surfaces, MDF for painted shaped panels, plywood for strength-to-weight, melamine-faced board for contract interiors. Reference formaldehyde class E1, FSC or PEFC certification, and relevant EN strength and stability tests.
Worked example
A user is 1750 mm tall. A desk at 750 mm with a chair seat at 450 mm gives a 300 mm difference - at the top of the recommended 250–320 mm range, so acceptable but not generous. Check knee clearance: desk top 750 mm minus a 60 mm apron leaves 690 mm, which clears the 620 mm minimum. If the user were 1600 mm, a 720 mm desk with a 430 mm seat would be better. The design passes, but only because the numbers were checked.
Traps that cost marks
Designing for the average person; forgetting door and drawer swing clearances (allow at least 300 mm from a wall); ignoring panel thickness in module planning; ignoring grain direction on drawer fronts; quoting a dimension without saying which user it suits.
Every design claim should be a number plus a reason.